Mystic Ambit Incant

The Mystic Ambit Incant is an artifact in Hexen. It is a scroll with a blue rune on it, and activating one has a different effect depending on which class is using it:
 * The Fighter gets a boost of one point to his armor class by adding durability to one of the four armor pieces. Like the Dragonskin Bracers, this is allowed to surpass the maximums for individual armor pieces, capped only by the class's total armor maximum.
 * The Cleric regains a significant portion of his health, if injured. (50 points plus an additional random amount from 0 to 49)
 * The Mage gets more mana. If the player can have any more blue mana, it will be added there. Green mana is given only if the blue was already full. (50 points plus an additional random amount from 0 to 49)
 * Pigs get no effect.

The effect will also be applied to all nearby players in co-op, thus it makes sense to gather together when using the Incants to get the most of them. Perhaps because of this multiplayer nature of the item, Incants, at least in the original game's maps, do not appear in single player.

Appearance statistics
In the IWADs the mystic ambit incant is first encountered on these maps per skill level:

The IWADs contain the following numbers of mystic ambit incants per skill level:

Trivia

 * "Ambit" means a sphere of influence or scope of actions/thoughts/words. This fits well with the multiplayer effect. Latin root: ambitus (circuit). You could roughly translate the item as "magical sphere-of-influence spell".
 * Due to incorrect programming, the fighter and mage effects are less potent than they should have been. It appears that the fighter's incant was intended to grant four points of armor (similarly to the Dragonskin Bracers), while the mage's would have given equal amounts of both blue and green mana.